Machine and method for fitting and removing a tyre

ABSTRACT

A machine for fitting and removing a tyre from a corresponding rim of a wheel of a vehicle, comprising: a wheel-holder unit rotating about a first axis (A) and slidably coupled to a groove provided in a base; a column; an upper operating head, provided with at least one upper fitting tool, at least one further tool, angularly spaced from the upper fitting tool, by a predetermined angle, and a wall pressing tool that can be placed in a working position which is operatively in contact with the wheel simultaneously with the upper fitting tool.

CLAIM TO PRIORITY

This continuation patent application claims priority to and benefit of,under 35 U.S.C. § 120, U.S. patent application Ser. No. 14/789,620,filed Jul. 1, 2015, titled “Machine And Method For Fitting And RemovingA Tyre”, which claims priority to and benefit of, under 35 U.S.C. §119(a), Italian Patent Application Serial Number BO2014A000374, filedJul. 3, 2014, all of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

This invention relates to a machine and a method for fitting andremoving a tyre.

To perform the removal of a tyre from a rim and the subsequent fittingoperation, the state of the art consists of tyre changer machines havinga wheel-holder unit and at least one operating unit.

The wheel-holder unit is designed to support and rotate the wheel aboutan axis. The operating unit comprises the tools used in differentoperating steps which entail:

-   -   detaching the bead of the tyre from the annular end (that is,        edge) of the rim (process also known as bead breaking);    -   removing the tyre from the rim, that is, removing the tyre from        the housing defined by the space between the two annular edges        of the rim;    -   fitting a new tyre on the rim, that is, positioning a new tyre        in the housing.

It should be noted that the expression “tyre changer machine” iscommonly understood to refer to a machine which is able to both removethe tyre from the rim and then perform the fitting operation. It shouldalso be noted that the term “bead” denotes the portion of the tyrerunning round the annular edge of the rim.

The wheel-holder unit comprises, for example, a locking system whichfixes the wheel to a rotary supporting plate. Typically, the axis ofrotation is vertical, even though it is preferable to adopt a solutionwith a horizontal axis if the machine is designed to operate on wheelsof heavy vehicles.

The operating unit usually comprises at least one bead breaker tool (orbead breaker disc). During use, the rubber of the tyre bead overheatsand the bead adheres to the rim due to a rubber vulcanization phenomena;it is therefore necessary to detach the bead from the edge of the rimbefore starting the removal step. During the bead breaking step, thewheel is rotated by the wheel-holder unit and the bead breaker toolexerts a pressure on the side wall of the tyre close to the bead causingdetachment from the edge of the rim.

It should be noted that a tyre has two beads, corresponding to the twoannular edges of the rim, so the tyre changer machines usually have apair of bead breaker disks, each of which is designed to act on acorresponding bead of the tyre.

The rotary wheel-holder unit has a free end, to which the wheel isfixed, and an opposite end, connected to a drive unit. The positioningof the wheel on the wheel-holder unit makes it possible to define alower side and a bead of the tyre, facing towards the end of thewheel-holder unit connected to the drive unit, and an upper side and abead of the tyre, facing in the opposite direction to the lower side.

For this reason, the tools designed to act on the upper bead arereferred to as upper tools, whilst the tools designed to act on thelower bead are referred to as lower tools.

In the tyre changer machines wherein the wheel-holder unit is configuredwith a vertical axis, the lower side and bead of the tyre face towardsthe supporting surface of the machine, that is to say, downwards, whilstthe upper side and bead of the tyre face in the opposite directionrelative to the lower side, that is to say, upwards.

The tyre changer machines are equipped with numerous tools, for beadbreaking, removal and fitting of the tyre; typically, the tyre changermachines have tools designed to operate (in the bead breaking, removaland fitting steps) on the upper bead of the tyre and other, different,tools designed to operate (in the bead breaking, removal and fittingsteps) on the lower bead of the tyre.

Each operating step requires the use of a specific tool or a specificcombination of tools. In light of this, it should be noted that,typically, each tool is mounted on a respective supporting arm, actuatedby a respective actuator and moved on a relative guide.

The presence of many movement apparatuses limits the vision of theoperator in the proximity of the zone in which the machine operates onthe wheel, hindering the freedom of movement of the operator.

This also translates into a significant increase in the dimensions ofthe tyre changer machines, which have a rather complex structure. Thecomplexity of the machines increases the production and maintenancecosts. Moreover, the increased complexity of these machines makes themmore difficult to use by the operator to detriment of the reliability,thereby increasing the risks of error.

A partial solution to these problems is provided by patent documentEP1479539, which has a machine having an operating head wherein a beadbreaker disc is connected to a fitting/removal tool; this tyre changingtool is moved by a mechanism which allows it to change from one workingposition (that is, operational) to a non-interference position (that is,rest).

Patent document EP2125394 shows a machine having a rotary operating headwith two tools; more specifically, the operating head has a bead breakerdisc and a removal tool. The rotation of the head allows the selectionof the tool. The same arm is connected to a fitting tool which, thanksto a hinge coupling, can be lowered or raised to adopt alternatively anoperating position or a non-interference position.

Patent document EP1946946 shows a machine having a rotary operating headwhich supports three tools (a bead breaker tool, a removal tool and afitting tool) arranged at 120°, in such a way as to be selectively andalternatively positionable in the operating position by rotating theoperating head.

However, these tyre changer machines also have certain shortcomings,because they do not allow the tyre to be mounted in a particularlysimple, reliable and comfortable fashion, with a particularly reducednumber of actions by the tyre repair specialist.

SUMMARY OF THE INVENTION

The aim of this invention is to provide a machine and a method forfitting and removing a tyre which overcome the above mentioned drawbacksof the prior art.

More specifically, the aim of this invention is to provide a machine anda method for fitting and removing a tyre which is particularly simpleand reliable. The greater simplicity of the machine results in areduction in costs.

A further aim of this invention is to provide a tyre changer machinehaving particularly reduced dimensions, to give the tyre repairspecialist a large space for operating and visibility.

A further aim of the invention is to provide a tyre changer machine thatis particularly robust and reliable.

These aims are fully achieved by the machine and method forming thesubject matter of this invention as characterised in the appendedclaims.

More specifically, the tyre changer machine according to the inventionis designed to take out/insert a tyre from/in a housing defined by theannular edges of a rim.

The tyre changer machine comprises a wheel-holder unit and at least oneoperating unit. The wheel-holder unit is configured to rotate about afirst axis of rotation, preferably vertical.

It should be noted that the adjectives “upper” and “lower” are used inthis document for convenience of description, without thereby limitingto specific spatial references, which remain arbitrary. The adjectives“upper” and “lower” are used to distinguish different functions ofmachine parts, without limiting to absolute spatial references.

In the embodiment illustrated, the wheel-holder unit is connected to abase for being moved in a direction perpendicular to the relative axisof rotation, that is, in the direction away from or towards theoperating unit.

In a possible embodiment of this invention, a column oriented verticallyis coupled to the base of the tyre changer machine. The column isequipped with a guide on which two carriages, an upper carriage and alower carriage, are slidably coupled. Preferably, the upper carriage andthe lower carriage are coupled to the same guide, for reducing thedimensions of the tyre changer machine according to this invention.

The upper carriage supports an upper arm having two ends. The first endof the upper arm is coupled to the upper carriage in such a way that itcan translate along and rotate about a second axis of rotation. Thesecond end of the upper arm is connected to an upper operating head.

The lower carriage supports a lower arm having two ends. The first endof the lower arm is coupled to the lower carriage. The second end of thelower arm is connected to a lower operating head.

The upper operating head comprises an upper fitting tool, having a shapewhich is elongate in a direction for being operatively inserted betweena bead of the tyre and an annular edge of the rim, and at least onefurther tool. Preferably, the further tool is an upper bead breaker discor a removal tool, the latter having a shape which is elongate in adirection to be inserted between the bead of the tyre and the edge ofthe rim.

The tools of the upper operating head are angularly spaced from eachother by a predetermined angle, to be selectively and alternativelypositionable in an operating configuration by rotation of the upperoperating head.

The tyre changer machine according to this invention comprises a wallpressing tool, connected to the upper operating head and oriented in adirection concordant with the upper fitting tool, for being positioned,in an operating position in contact with the wheel, simultaneously withthe upper fitting tool.

This makes it possible to simultaneously select the upper fitting tooland the wall pressing tool by simply rotating the upper operating head,thereby reducing the complexity of the machine. Preferably, thepositioning of the upper tools in the operating positions, in contactwith the wheel, is made possible by a movement of the wheel-holder unit(by translating along a direction perpendicular to the axis of rotationof the wheel-holder unit) and/or by translating the upper arm in adirection parallel to the axis of rotation of the wheel-holder unit(using the upper carriage) and perpendicularly to the axis of rotationof the wheel-holder unit (by a movement of extension and withdrawal ofthe upper arm with respect to the upper carriage).

In effect, the upper fitting tool and the wall pressing tool dedicatedto the working on the upper bead are connected to the same upperoperating head and have a fixed spatial relationship.

It should be noted that, preferably, the upper fitting tool has anelongate shape; preferably, elongate along a longitudinal axis containedin a plane parallel to the axis of rotation of the wheel-holder unit andperpendicular to the axis of rotation of the upper operating head.

Moreover, preferably, the upper fitting tool has an end configured forcoupling with the upper operating head and a free end (if necessary,shaped) to operate on the tyre. Preferably, the upper fitting tool, inits operating configuration, is oriented (elongate) along a longitudinalaxis which is substantially parallel to the axis of rotation of thewheel-holder unit (that is to say, to the first vertical axis ofrotation).

With regard to the spatial relationship between the upper fitting tooland the wall pressing tool connected to the upper operating head,attention is drawn to the following.

According to some embodiments, the wall pressing tool is positionedlaterally at a predetermined distance relative to a plane passingthrough the first vertical axis of rotation and through the upperfitting tool.

This ensures that, when the upper fitting tool and the wall pressingtool are operatively and simultaneously active on the tyre, the wallpressing tool presses on a zone of the tyre located laterally (angularlyspaced by a predetermined quantity along a circumference defined by thebead of the tyre) relative to the zone in which the upper fitting toolis active. It should be noted that, in order to operate, the wallpressing tool must press on a portion of the tyre in which the bead hasalready been inserted inside the housing defined by the edges of therim. Consequently, the position of the wall pressing tool relative tothe upper fitting tool is determined by the direction of rotation of thewheel rotated by the wheel-holder unit.

Moreover, the distance of the wall pressing tool from the first verticalaxis of rotation is greater than the distance at which the upper fittingtool is located.

This ensures that, when the upper fitting tool and the wall pressingtool are operatively and simultaneously active on the tyre, the wallpressing tool presses on a zone of the side of the tyre, whilst theupper fitting tool acts on the bead of the same tyre.

Moreover, the wall pressing tool is positioned at a greater distancefrom the upper operating head than the upper fitting tool, in thedirection of the first axis of rotation of the wheel-holder unit (thatis, of the longitudinal axis of the upper fitting tool). Thisfacilitates a pushing action on the side of the tyre when the upperfitting tool is positioned for operating between bead and edge of therim.

It should also be noted that the solution proposed by this inventionincreases the reliability of the machine, since it reduces thepossibility of error by the operator by limiting the number ofoperations the operator needs to perform, for example, the manualpositioning of the wall pressing tool in its operating position.

The wall pressing tool comprises a contact element configured to rotateabout its axis of rotation when, in the operating position, the side ofthe wheel is pressed. Preferably, the contact element has an ogivalshape in order to better adapt to the side of different types of tyres;however, this does not exclude any use of a contact element having adisc shape, that is to say, a shape similar to that typically used forthe bead breaker discs.

According to some embodiments, the wall pressing tool is connected tothe upper fitting tool; preferably, the wall pressing tool is connectedto the upper fitting tool in a rigid fashion. According to thisinvention, the connection is made using a connecting arm; preferably,the connecting arm is fixed to the upper fitting tool in an intermediatezone between the portion configured for the connection with the upperoperating head and the portion configured to operate on the tyre. Theembodiment illustrated limits the length of the connecting arm, thusreducing the intensity of the stress to which it is subjected in anoperating step, thus increasing the useful life.

In an embodiment, the upper operating head of the tyre changer machinecomprises, in addition to the upper fitting tool coupled with the wallpressing tool, two further tools, that is, an upper bead breaker discand a removal tool. The tools fixed to the upper operating head areangularly spaced from each other by a predetermined angle, to beselectively and alternatively selectable in an operating configurationby rotation of the upper operating head.

The particular embodiment therefore defines three operatingconfigurations:

-   -   a first operating configuration wherein the upper bead breaker        disc is oriented towards the upper side of the tyre;    -   a second operating configuration wherein the removal tool is        oriented towards the upper side of the tyre;    -   a third operating configuration wherein the upper fitting tool        and the wall pressing tool connected to it are simultaneously        oriented towards the upper side of the tyre.

It should be noted that, according to this invention, there is at leastone operating configuration wherein two tools can be selectedsimultaneously, that is, the upper fitting tool and the wall pressingtool.

It should be noted that the angular distance which separates the toolsmounted on the operating head allows the tool operating on the wheel notto interfere with the inactive tools. It should be noted that thissolution allows the grouping together, on the upper operating head, ofall the tools configured to operate in a stationary position relative tothe wheel rotated by the wheel-holder unit and designed to work on theside wall and on the upper bead of the tyre during the tyre fitting andremoval steps. It should be noted that the tools can be selected byrotating the upper operating head. Preferably, the rotation iscontrolled when the upper operating head is at a distance such as toguarantee the non-interference of the wheel with the tools fixed to theupper operating head. Preferably, the upper tools have respective endsdistal from the upper arm (that is, from the upper head) lying in aplane perpendicular to the second axis of rotation, that is, the axis ofrotation of the upper operating head.

It should be noted that the upper fitting tool and the wall pressingtool are fixed to the upper operating head to act in conjunction,thereby being simultaneously in the active configuration orsimultaneously in the non-interference configuration; that is to say,the upper fitting tool and the wall pressing tool are either bothactivated (in the active configuration) or both deactivated (in thenon-interference configuration); this is also thanks to the fact thatthe head rotates between separate predetermined positions.

This reduces the possibility of error of the tyre repair specialist.

In an embodiment, the rotation of the operating head between thepossible operating configurations is controlled by a first actuator,with three stages. The first actuator defines a first stage wherein theupper operating head is positioned in the first operating configuration,a second stage wherein the upper operating head is positioned in thesecond operating configuration, a third stage wherein the upperoperating head is positioned in a third operating configuration, therebydefining a predetermined sequence as a function of a predetermineddirection of rotation (that is to say, forwards) of the upper operatinghead. The first actuator is connected to a control unit; the controlunit controls the movement of the first actuator from one stage to theother, according to the following predetermined sequence of stages:first stage, second stage, third stage, wherein the passage from thefirst stage to the second stage and the passage from the second stage tothe third stage correspond to a rotation of the upper operating headaccording to the forwards direction and the passage from the third stageto the first stage corresponds to a rotation of the upper operating headin an opposite direction (that is, backwards).

This increases the reliability of the tyre changer machine; theintroduction of an actuator and a predetermined sequence of operationslimits the risk of error by the operator, whose duty is merely that ofactivating the control unit of the actuator. The first actuator operatestogether with a first system for locking of the rotation, which preventsrotation of the upper arm during each operational step. Preferably, thefirst system for locking the rotation comprises a pin controlledelectrically, for example using a second actuator, but other solutionsare not excluded.

The lower operating head of the tyre changer machine comprises at leasttwo lower tools angularly spaced from each other by a predeterminedangle, to be selectively and alternatively positionable in an operatingconfiguration by rotation of the lower operating head. Preferably, thelower tools, fixed to the lower operating head, are angularly spaced byan angle of 90 degrees.

Preferably, the lower tools have respective ends distal from the lowerarm (that is, from lower upper head) lying in a plane perpendicular tothe third axis of rotation, that is, the axis of rotation of the loweroperating head.

Preferably, the lower tools comprise a lower bead breaker disc and alower fitting tool. It should be noted that, preferably, the lowerfitting tool has an elongate shape; preferably, elongate along alongitudinal axis contained in a plane parallel to the axis of rotationof the wheel-holder unit and perpendicular to the axis of rotation ofthe lower operating head.

Moreover, preferably, the lower fitting tool has an end configured forcoupling with the lower operating head and a free end (if necessary,shaped) to operate on the tyre. Preferably, the lower fitting tool, inits operating configuration, is oriented (elongate) along a longitudinalaxis which is substantially parallel to the axis of rotation of thewheel-holder unit (that is to say, to the first vertical axis ofrotation).

The embodiment illustrated allows at least two tools, designed to act onthe lower bead, to be integrated on a single operating head (the onededicated to working on the lower bead of the tyre). The lower operatinghead is supported and moved by a single arm, with a consequent reductionof the overall dimensions and the actuators necessary to move the toolsinto the respective operating positions in contact with the wheel. Itshould be noted that, preferably, the positioning of the lower tools inthe operating positions, in contact with the wheel, is made possible bya movement of the wheel-holder unit (by translating along a directionperpendicular to the axis of rotation of the wheel-holder unit) and/orby translating the lower arm in a direction parallel to the axis ofrotation of the wheel-holder unit (using the lower carriage) andperpendicularly to the axis of rotation of the wheel-holder unit (by amovement of extension and withdrawal of the lower arm with respect tothe lower carriage).

Preferably, the lower fitting tool is configured to adopt two positions,an active one and a rest one. Preferably, the lower fitting tool rotatesabout a fourth axis “D”, transversal to the axis of rotation “C” of thelower operating head, to pass from the rest position to the activeposition.

Preferably, the lower fitting tool in the rest position is angled by atleast 70 degrees relative to the same tool in the active position. Inother words, the rotation of the lower fitting tool must preferably begreater than 70 degrees to allow the lower fitting tool to pass from therest position to the active position.

This solution allows a reduction in the minimum angular distance whichthere must be between the tools of the lower operating head to avoidinterference. Moreover, the reduction in the angular distance allows areduction of the overall dimensions; the tools of the lower operatinghead never occupy the lower part of the head, without limiting,therefore, the stroke of the lower carriage to avoid interference withthe base of the tyre changer machine.

This invention also defines a method for fitting (and removing) a tyrerelative to a corresponding rim of a vehicle wheel, comprising thefollowing steps:

-   -   preparing a rotary wheel-holder unit;    -   preparing a rotating upper operating head equipped with an upper        fitting tool and at least one further tool;    -   preparing a wall pressing tool connected to the upper operating        head and oriented in a direction concordant with the upper        fitting tool for being positioned in a working position at the        same time as the upper fitting tool;    -   preparing a lower operating head equipped with at least one        lower bead breaker tool and at least one lower fitting tool,        angularly spaced for being selectively and alternatively        positionable by rotating the lower operating head into an        operating configuration, wherein the tool selected is oriented        towards the wheel mounted on the wheel-holder unit;    -   fixing the wheel to the wheel-holder unit;    -   rotating the lower operating head for selecting the lower        fitting tool, orienting it towards the lower side of the wheel;    -   moving the lower fitting tool towards an upper edge of the rim,        by moving a lower carriage, for positioning the lower fitting        tool in its working position, between a lower bead of the tyre        and the upper edge of the rim;    -   rotating the wheel-holder unit and the wheel fixed thereto to        insert the lower bead of the tyre inside a housing defined by        the edges of the rim;    -   stopping the rotation of the wheel-holder unit and the wheel        fixed to it at the end of the insertion of the lower bead inside        the housing of the rim;    -   moving the lower operating head away from the wheel;    -   rotating the upper operating head in an operating configuration        wherein the upper fitting tool and the wall pressing tool are        oriented towards an upper side of the wheel, in such a way that        the tools can be positioned simultaneously in the respective        operating positions in contact with the wheel;    -   moving the upper operating head towards the wheel by moving an        upper carriage and by relative movement of the upper operating        head and the wheel-holder unit to simultaneously move the upper        fitting tool and the wall pressing tool in the respective        operating positions in contact with the wheel;    -   rotating the wheel-holder unit and the wheel fixed thereto.

In a particular embodiment, the upper operating head comprises threetools angularly spaced from each other by a predetermined angle, to beselectively and alternatively positionable in an operating configurationby rotation of the upper operating head.

More specifically, when the tools are the upper bead breaker tool, theremoval tool and the upper fitting tool connected to the wall pressingtool, the method comprises a step of generating a rotational movement ofthe upper operating head in a predetermined direction suitable forselecting an operating configuration of the upper operating headselecting, in sequence:

-   -   the upper bead breaker tool,    -   the removal tool,    -   the upper fitting tool and the wall pressing tool connected to        it.

In the particular embodiment in which the rotation of the upperoperating head between the possible operating configurations iscontrolled by a first three-stage actuator, the tyre changer machinecomprises a mechanism for locking the rotation of the upper head. Inthis case, the method also comprises the following steps:

-   -   disconnecting a first system for locking the rotation of the        upper end;    -   rotating, using a first three-stage actuator, the upper        operating head until it reaches an operating configuration        between the first, second and third operating configurations;    -   reconnecting the first locking system when reaching the        predetermined operating configuration.

Preferably, the disconnection and the reconnection are performedautomatically. Preferably, the disconnection and the reconnection of thepin are controlled by a second electro-mechanical actuator.

Preferably, the tools coupled to the upper operating head (upper fittingtool, removal tool, upper bead breaker disc and wall pressing tool) haverespective ends distal from the upper arm lying substantially in a planeperpendicular to the axis of rotation of the upper operating head.

Preferably, the tools coupled to the lower operating head (lower fittingtool, lower bead breaker disc) have respective ends distal from thelower arm lying substantially in a plane perpendicular to the axis ofrotation of the lower operating head.

This prevents the risk of interference with the rim by tools positionedin a deactivated position, during the use of a tool (connected to thesame operating head) which, on the contrary, is in the activatedposition, that is to say, in the relative operating configuration.

In a particular embodiment, the lower fitting tool is movable between arest position and an active position, and is configured to adoptalternatively the rest position or the active position. In this case,the method also comprises the step of moving the lower fitting tool froma rest position to an active position.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other features of the invention will become more apparent fromthe following detailed description of a preferred, non-limiting exampleembodiment of it, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view with some parts cut away in order to betterillustrate others of a tyre changer machine according to this invention;

FIGS. 2 and 3 show a perspective view and a side view, respectively, ofa construction detail of the tyre changer machine of FIG. 1, accordingto this invention;

FIG. 4 shows a front view of a tool holder head according to thisinvention;

FIG. 5 illustrates the cross-section V-V of FIG. 3, with some parts cutaway to better illustrate others;

FIG. 6 illustrates the cross-section VI-VI of FIG. 3, with some partscut away to better illustrate others;

FIGS. 7 and 8 show perspective views of a construction detail of thetyre changer machine of FIG. 1 according to this invention, wherein alower fitting tool is in two corresponding different positions, thefirst a rest position and the second an operational position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying drawings, the numeral 1 denotes amachine for fitting and removing a tyre 2 from a corresponding rim 3 ofa wheel 4 (that is, a tyre changer machine) according to this invention.

The machine 1 comprises a base 5. The base 5 comprises a wheel-holderunit 6. The wheel-holder unit 6 is designed to house the wheel 4 and torotate it about a first axis of rotation “A”, in order to allow theabove-mentioned removing and fitting operations. Preferably, the firstaxis of rotation “A” is vertical.

The wheel-holder unit 6 comprises a hollow shaft, connected to rotationmeans (not shown), and a perforated supporting surface (not shown, ofknown type) to allow a clamping tool (or rod) 7 to pass through.Typically, the clamping rod 7 (of known type) is defined by alongitudinal shaft having a conical, intermediate or end, portion 7 a,for the purpose of centering the wheel 4.

The wheel 4 is locked so as to rotate as one with the shaft of thewheel-holder unit 6. For this purpose, after positioning the wheel 4 onthe supporting surface, the clamping rod 7 is inserted in the hole ofthe wheel-holder unit 6 and then tightened, by means of a suitablemechanism, to keep the conical portion pressed on the rim 3.

When the wheel 4 is placed on a supporting surface with a vertical axis,the tyre 2 has a lower side facing towards the base 5 and an upper sidefacing in an opposite direction relative to the lower side. Each of thetwo sides comprises a bead, that is to say, the reinforced edge of thetyre 2, in contact with the annular edge of the rim 3. The bead of theupper side will hereafter be referred to as the upper bead and,similarly, the bead of the lower side will hereafter be referred to asthe lower bead. The edge of the rim 3 corresponding to the upper beadwill hereafter be referred to as the upper edge and, similarly, the edgecorresponding to the lower bead will hereafter be referred to as thelower edge. The space between the two annular edges of the rim definesthe housing in which the tyre is positioned, during the fitting step, orfrom which the tyre is removed, during the removing step. It should benoted that in the following description the adjectives “upper” and“lower” are used without thereby intending to limit the scope ofprotection afforded by the invention to the fact that the axis ofrotation of the wheel is perpendicular to the supporting surface of themachine (“vertical axis”; this is preferred embodiment), since the axismight also be “horizontal” or oriented in another way.

The wheel-holder unit 6 is coupled to the base 5 for being moved in thedirection perpendicular to the first axis of rotation “A”. Morespecifically, the wheel-holder unit 6 comprises a plate 9 integral withit. The plate 9 covers a groove in the base 5, the groove having thepurpose of a guide for the shaft of the wheel-holder unit 6. It shouldbe noted that the plate 9 prevents the accidental falling of objects inthe groove, preventing damage to the tyre changer machine 1.

In the embodiment illustrated, the tyre changer machine 1 comprises,associated with the base 2, a column 8 extending in a direction parallelto the first axis of rotation “A”. Preferably, the column 8 extendsvertically. The wheel-holder unit 6 may therefore be moved towards oraway from the column 8, allowing the tyre changer machine 1 to operateon tyres with different diameters.

The column 8 comprises a guide 10 extending along the main direction ofextension of the column 8. An upper carriage 11 is slidably constrainedto the guide 10 to move along the guide 10 upwards or downwards. A firstmovement system 12 is associated with the upper carriage 11 with thepurpose of moving the upper carriage 11 between a first upper endposition and a second lower end position along the guide 10.

The first movement system 12 associated with the upper carriage 11comprises a first piston 12 a. The first piston 12 a comprises an axialhole for being slidably coupled to a first guide rod 12 b. Morespecifically, the first rod guide 12 b is integral with the column 8 andthe upper end of the first piston 12 a is coupled to the upper carriage11.

An upper arm 15 comprises a first and a second end. The first upper endof the arm 15 is coupled to the upper carriage 11. More specifically,the coupling is such as to allow the rotation of the upper arm 15 abouta second axis of rotation “B”. Preferably, the second axis of rotation“B” is perpendicular to the axis of rotation “A”. Preferably, the secondaxis of rotation “B” is parallel to the direction in which thewheel-holder unit 6 can be moved relative to the base 5. The second endof the upper arm 15 is connected to an upper operating head 16, fixed tothe upper arm 15.

A lower carriage 13 is slidably constrained to the guide 10 to movealong the guide 10 upwards or downwards. A second movement system 14 isassociated with the carriage lower 13 to move the lower carriage 13between a first lower end position and a second upper end position alongthe guide 10. Preferably, the upper carriage 11 and the carriage lower13 are slidably constrained to the guide 10.

The second movement system 14 associated with the lower carriage 9comprises a second piston 14 a. The second piston 14 a comprises anaxial hole for being slidably coupled to a second guide rod 14 b. Morespecifically, the second rod guide 14 b is integral with the column 8and the lower end of the second piston 14 a is coupled to the lowercarriage 13.

A lower arm 23 comprises a first and a second end. The first end of thelower arm 23 is fixed to the lower carriage 13. The second end of thelower arm 23 is coupled to a lower operating head 24.

The upper operating head 16 consists of a body 17 comprising at leastone upper fitting tool 18 and at least one further tool. The upperfitting tool 18 is defined by a body having an elongate shape in adirection for being operatively inserted between the upper bead of thetyre 2 and the upper edge of the rim 3, for positioning a first portionof the upper bead inside the housing of the rim 3.

Preferably, the upper fitting tool 18 and the further tool are angularlyspaced from each other by a predetermined angle to be selectively andalternatively positionable in an operating configuration (that is tosay, a working configuration) by rotation (that is to say, rotationalmovement) of the upper operating head 16.

Even more preferably, the upper fitting tool 18 and the further tool areangularly equidistant.

Preferably, the further tool is an upper bead breaker tool 19 or removaltool 20. The removal tool 20 has an elongate shape in a direction, forexample claw-like, for being inserted between the upper bead of the tyre2 and the upper edge of the rim 3, for gripping and extracting a portionof the upper bead from the housing of the rim 3. The upper bead breakertool 19 comprises a circular body 19 a supported by a supporting arm 19b. The circular body 19 a is configured for pressing on the upper beadof the tyre 2 towards the lower bead, for causing the detachment fromthe upper edge of the rim 3. The coupling between the circular body 19 aand the supporting arm 19 b allows the circular body 19 a to rotate incontact with the wheel 4 when located in the working position.

According to this invention, a wall pressing tool 21 is connected to theupper operating head 16, preferably in a rigid fashion.

The wall pressing tool 21 is oriented in a direction concordant with theupper fitting tool 18 so it can be placed in a working position, whichis operatively in contact with the wheel, simultaneously with the upperfitting tool 18.

Preferably, the wall pressing tool 21 is directly connected to the upperfitting tool 18. Preferably, the wall pressing tool 21 is connected tothe upper fitting tool 18 by a connecting arm 22.

In the particular embodiment illustrated, the connecting arm 22 has twoends. The first end of the connecting arm 22 is connected to the upperfitting tool 18. The second end of the connecting arm 22 is coupled tothe contact element 21 a of the wall pressing tool 21. The couplingbetween the contact element 21 a and the connecting arm 22, allows thecontact element 21 a to rotate when, in the operating position, it is incontact with the wheel 4 rotated by the wheel-holder unit 6. Preferably,the contact element 21 a has an ogival shape in order to better adapt tothe profile of different types of tyres 2.

In the embodiment illustrated, in addition to the upper fitting tool 18coupled to the wall pressing tool 21, the upper operating head 16comprises two further tools, the upper bead breaker disc 19 and theremoval tool 20. The upper operating head 16 is thus configured to adoptthree operating configurations:

-   -   a first operating configuration wherein the bead breaker disc 19        is oriented towards the upper side of the tyre 2;    -   a second operating configuration wherein the removal tool 20 is        oriented towards the upper side of the tyre 2;    -   a third operating configuration wherein the upper fitting tool        18 and the wall pressing tool 21 connected to it are        simultaneously oriented towards the upper side of the tyre.

Preferably, the tools 18, 19 and 20, fixed to the upper operating head16, are angularly spaced by an angle of 120°, which guarantees thenon-interference between the operating tool (or pair of tools) and theinactive tools. Preferably, the tools 18, 19, 20 of the upper operatinghead 16 have respective ends distal from the upper arm 15 lying in aplane perpendicular to the second axis of rotation “B”.

During the various operating steps, the tools are subjected to forcesderiving from the contact with the wheel 4 rotated by the wheel-holderunit 6. These forces tend to rotate the operating tool (as well astranslate in a direction parallel to the axis of the wheel, because thetyre is partly elastic). The body 17 of the upper operating head 16 istherefore shaped to house in the base the tools 18, 19, 20 and preventthe above-mentioned movements. More specifically, the body 17 of theupper operating head 16 has an outer face to which the tools 18, 19, 20are fixed.

Preferably, the body 17 of the upper operating head 16 comprises radialgrooves (defined on the outer face); the radial grooves have side wallsin contact with the base of the tools and constitute a rotation lock byinterference, to prevent an accidental rotation of the tools 18, 19, 20relative to the upper operating head 16. Therefore, preferably, eachradial groove houses the base of a tool.

The rotational movement of the upper arm 15 is controlled by a firstactuator 25. The first actuator 25 moves a rack 26 coupled to a gearwheel 27. The gear wheel 27 is coupled to the upper arm 15 to rotatearound the axis of rotation “B”.

More specifically, the first end of the upper arm 15 is closed by a cap28 fixed to the upper arm 15 by radial fixing elements 29. The cap 28has a shaped face 28 a, perpendicular to the axis of rotation of theupper arm 15, for housing the gear wheel 27. The gear wheel 27 is fixedto the shaped face 28 a by means of axial locking elements 29.Preferably, the first actuator 25 is a three-stage actuator, forrotating the upper operating head 16 between the three above-mentionedoperating configurations. The first actuator 25 has a first stagewherein the upper operating head 16 is positioned in the first operatingconfiguration, a second stage wherein the upper operating head 16 ispositioned in the second operating configuration, a third stage whereinthe upper operating head 16 is positioned in a third operatingconfiguration, thereby defining a predetermined sequence (first stage,second stage, third stage) as a function of a predetermined direction ofrotation (that is to say, forwards) of the upper operating head 16. Acontrol unit 41 is connected to the first actuator 25 to control themovement of the first actuator 25 from one stage to the other. Thepassage from the first stage to the second stage and the passage fromthe second stage to the third stage correspond to a rotation of theupper operating head 16 according to the forwards direction, whilst thepassage from the third stage to the first stage corresponds to arotation of the upper operating head 16 in an opposite direction (thatis, backwards).

During each operating step, the rotational motion of the upper arm 15 islocked by a first system 30 for locking the rotation. Preferably, thefirst system 30 for locking the rotation comprises a first pin 30 adesigned to be inserted in a radial hole 31 made in the side wall 28 bof the cap 28. In the embodiment illustrated, wherein the upperoperating head 16 can adopt alternatively three operatingconfigurations, the lateral surface of the cap 28 has three radial holes31 (FIG. 6), angularly spaced by 120°.

Preferably, the disconnection and reconnection of the first pin 30 a arecontrolled by a second actuator. The second actuator controls theinsertion of the first pin 30 a when the upper arm 15 has finished itsrotational movement to reach a certain operating position. It should benoted, however, that the insertion control might be performed during therotational movement, that is, during the passage between two differentoperating positions of the upper arm 15, if a spring exerts a force onthe pin which is able to automatically insert it when it is at one ofthe radial holes 31.

In the particular embodiment illustrated, the machine 1 also comprises athird actuator 42 for moving the upper arm 15 in the direction of thesecond axis of rotation “B”. It should be noted that the movement of theupper arm 15 causes the movement of the components connected thereto, inparticular the upper operating head 16, the first actuator 25, the rack26, the gear wheel 27 and the locking system 30, thereby defining anupper operating unit integral with the upper arm 15 in the translationalmotion controlled by the third actuator 42.

The third actuator 42 moves the upper arm 15 between a working position,wherein the tools of the upper head 16 are aligned with the edge of therim 3 to perform all the operations, and a disengaged position whereinthe upper operating head 16 is away from the working zone, to facilitatethe operations for positioning and removing the wheel 4 on and from thewheel-holder unit 6. Preferably, the third actuator 42 has two stages.Preferably, the third actuator 42 is a cylinder with two stages.

The lower operating head 24 is coupled to the second end of the lowerarm 23 and provided with at least one lower tool designed to operate ona lower side of the tyre.

Preferably, the lower operating head 24 comprises at least two tools,that is, a lower bead breaker disc 32 and a lower fitting tool 33. Thelower bead breaker disc 32, in a similar manner to the upper beadbreaker disc 19, is configured for pressing on the lower bead of thetyre 2 and rotating about a relative axis when it is in contact with thewheel 4 rotated by the wheel-holder unit 6. The lower fitting tool 33 isdefined by a body having an elongate shape in a direction for beingoperatively inserted between the lower bead of the tyre 2 and the upperedge of the rim 3, for positioning, at the start of the fitting step,the lower bead inside the housing of the rim 3.

Preferably, the tools of the lower operating head 24 are spaced radiallyby a predetermined angle, to be selectively and alternativelypositionable in an operating configuration by rotation of the loweroperating head 24 about a third axis of rotation “C”. Preferably, thethird axis of rotation “C” and the second axis of rotation “B” arecoplanar or parallel. Preferably, the tools of the lower operating headare spaced radially by an angle of 90°, to limit the overall dimensionsin the proximity of the base 5. Preferably, the tools 32, 33 of theupper operating head 24 have respective ends distal from the lower arm23 lying in a plane perpendicular to the third axis of rotation “C”.

It should be noted that the lower operating head 24 is thus configuredto adopt two operating configurations:

-   -   a first operating configuration wherein the lower bead breaker        disc 32 is oriented towards the lower side of the wheel 4;    -   a second operating configuration wherein the lower fitting tool        33 is oriented towards the lower side of the wheel 4.

The lower arm 23 comprises a second locking system 34, for locking therotation of the lower operating head 24 in each of the possibleoperating configurations. Preferably, the second locking systemcomprises a second pin 34 a.

The lower fitting tool 33 is configured to adopt alternatively a restposition (FIG. 7), adopted during the first operating configuration ofthe lower operating head 24, or an active position (FIG. 8), adoptedduring the second operating configuration of the lower operating head24. Preferably, the lower fitting tool 33 rotates between the activeposition and the rest position by means of a hinge mechanism 35.Preferably, the axis of rotation of the hinge mechanism 35 isperpendicular to the third axis of rotation “C”.

It should be noted that the hinge mechanism 35 comprises a return spring36 connected to the lower fitting tool 33 to oppose its movement bothaway from the rest position and away from the active position. In theparticular embodiment illustrated, when the tool is in the activeposition, the return spring 36 extends during a portion of the rotationof the lower fitting tool 33 towards the rest position, generating aforce which opposes the movement. After performing a rotation by apredetermined angle, the return spring 36 exceeds a dead point andstarts to shorten, applying a force which facilitates the movement ofthe lower fitting tool 33 to the rest position. The opposite occursduring the movement of the tool from the rest position to the activeposition. It should be noted that, by adopting this solution, the activeposition and the rest position are stable positions for the lowerfitting tool 33.

It should also be noted that the base of the lower fitting tool 33 isconnected to the hinge mechanism 35 by a shaped plate 37 equipped withan anti-rotation shoulder 37 a.

In the embodiment illustrated, the tyre changer machine 1 also comprisesan auxiliary tool 38 which can be associated with the upper side of thetyre 2 during the fitting step. The auxiliary tool 38 is configured forpressing on the upper side wall of the tyre, in a zone in which theupper bead has already been inserted in housing of the rim 3. In itsoperating step, the auxiliary tool 38 is integral with the wheel 4rotated by the wheel-holder unit 6.

In the particular embodiment illustrated, the auxiliary tool 38 isconnected to the column 8 by means of an articulated arm 39 which allowsthe movement in a plane perpendicular to the first axis of rotation “A”.The auxiliary tool 38 is moved in a direction parallel to the first axisof rotation “A” by a fourth actuator 40, coupled to the articulated arm39.

This invention also provides a method for fitting/removing the tyre 2on/from the corresponding rim 3 of the wheel 4. It should be noted thatthe following description does not limit the scope of protection to theparticular embodiment described.

The removal operation comprises a preliminary procedure for breaking thebead of the tyre, followed by the actual removal, according to thefollowing steps:

-   -   preparing a rotatable wheel-holder unit 6;    -   fixing the wheel 4 to the wheel-holder unit 6;    -   moving the wheel-holder unit 6 towards the column 8, and/or        moving the upper arm 15 towards the wheel-holder unit 6;    -   preparing the upper operating head 16 in its first operating        configuration, that is to say, selecting the upper bead breaker        disc 19;    -   preparing the lower operating head 24 in its first operating        configuration, that is to say, selecting the lower bead breaker        disc 32;    -   moving the upper operating head 16 towards the wheel 4 by moving        the upper carriage 11 to carry the upper bead breaker tool 19        into contact with the upper bead of the tyre 2;    -   moving the lower operating head 24 towards the wheel 4 by moving        the lower carriage 13 to carry the lower bead breaker tool 32        into contact with the lower bead of the tyre 2;    -   rotating the wheel-holder unit 6 and the wheel 4 fixed thereto;    -   stopping the rotation of the wheel-holder unit 6 and of the        wheel 4 fixed to it upon completion of the bead breaking step        (at this point, the bead breaking is completed);    -   moving the upper operating head 16 away from the wheel 4 by        moving the upper carriage 11, to allow rotation of the upper        operating head 16 and changing of the tool;    -   moving the lower operating head 24 away from the wheel 4 by        moving the carriage lower 13;    -   operating the control unit 41 so as to carry the upper operating        head 16 to the second operating configuration, that is to say,        selecting the removal tool 20; the operation of the control unit        41 comprises the automatic disconnection of the first system 30        for locking the rotation of the upper arm 15 and its subsequent        connection when the second operating configuration is reached;    -   moving the upper operating head 16 towards the wheel 4 by moving        the upper carriage 11, to insert the removal tool 20 between the        upper bead of the tyre 2 and the upper edge of the rim 3;    -   moving the upper operating head 16 away from the wheel 4 to        allow the removal tool 20 to carry the upper bead of the tyre 2        beyond the upper edge of the rim 3;    -   rotating the wheel-holder unit 6 and the wheel 4 fixed thereto;    -   when the upper bead of the tyre 2 has a completely passed the        upper edge of the rim 3, lifting of the lower operating head 24        to allow the lower bead of the tyre 2 to also escape from the        housing defined by the edges of the rim 3;    -   stopping the rotation of the wheel-holder unit 6 and of the        wheel 4 fixed to it upon completion of the removal step;    -   moving the upper operating head 16 away from the wheel 4 by        moving the upper carriage 11, to facilitate movement of the tyre        2 completely detached from the rim 3, and allow rotation of the        upper operating head 16 for changing of the tool.

The fitting of the tyre 2 on the rim 3 comprises the following operatingsteps:

-   -   selecting the lower fitting tool 33 on the lower operating head        24, if necessary by rotating the head;    -   moving the lower operating head 24 towards the wheel 4 by moving        the lower carriage 13, to carry the lower fitting tool 33        between the lower bead of the tyre 2 and the upper edge of the        rim 3;    -   rotating the wheel-holder unit 6 and the wheel 4 fixed thereto;    -   stopping the rotation of the wheel-holder unit 6 and the wheel 4        fixed to it at the end of the insertion of the lower bead inside        the housing of the rim 3;    -   moving the lower operating head 24 away from the wheel 4 by        moving the carriage lower 13;    -   operating the control unit 41 to carry the upper operating head        16 to its third operating configuration (that is, selecting the        upper fitting tool 18 coupled to the wall pressing tool 21);        this step may also occur at the start of the fitting step;    -   moving the upper operating head 16 towards the wheel 4 by moving        the upper carriage 11 (parallel to the axis “A” of the        wheel-holder unit) and by relative movement of the upper        operating head 16 and the wheel-holder unit 6 perpendicularly to        the axis of the wheel-holder unit “A”, to carry the tools 18, 21        to the respective operating positions in contact with the wheel        4; once the desired pair of tools has been selected, by rotating        the upper operating head 16, the upper operating head 16 itself        is moved towards the wheel 4 until the tools 18, 21 are in the        respective operating positions; more specifically, the upper        fitting tool 18, in its working position, is in contact with the        tyre and is inserted between the upper bead of the tyre 2 and        the upper edge of the rim 3 to simultaneously operate the wall        pressing tool 21, positioned on the upper side of the wheel 4;        the operation of the control unit 41 comprises the automatic        disconnection of the first system 30 for locking the rotation of        the upper arm 15 and its subsequent automatic connection when        the third operating configuration is reached;    -   rotating the wheel-holder unit 6 and the wheel 4 fixed thereto;    -   stopping the rotation of the wheel-holder unit 6 and of the        wheel 4 fixed to it upon completion of the fitting step.

What is claimed is:
 1. A machine for fitting and removing a tyre from acorresponding rim of a wheel for a vehicle, comprising: a wheel-holderunit that is rotatable about a first vertical axis of rotation; a baseprovided with a groove, wherein the groove guides a movement of thewheel-holder unit with respect to the base; a column having a guideoriented vertically; an upper arm having a first end and a second end;an upper carriage coupled to the guide of the column and connected tothe first end of the upper arm; an upper operating head, connected tothe second end of the upper arm and provided with an upper fitting tool,the upper fitting tool defining a lever having an elongate shape along alongitudinal direction, and being configured to be operatively insertedbetween a bead of the tyre and an annular edge of the corresponding rim,in an operating configuration in which the upper fitting tool isoriented towards the wheel, to be positioned in a working position incontact with the tyre by translation of the upper operating head; a wallpressing tool connected to the upper operating head and oriented in adirection concordant with the upper fitting tool for being positionedsimultaneously with the upper fitting tool in a working position,wherein the wall pressing tool and the upper fitting tool are both;simultaneously in contact with the tyre of the wheel positioned on thewheel-holder unit; wherein the upper operating head includes aconnecting arm, the connecting arm having a first end, connected to theupper operating head or to the upper fitting tool, and a second end;and, wherein the wall pressing tool includes a contact element rotatablycoupled to the second end of the connecting arm.
 2. The machineaccording to claim 1, further comprising a plate configured to cover thegroove.
 3. The machine according to claim 2, wherein the plate isintegral with the wheel-holder unit.
 4. The machine according to claim1, wherein the wall pressing tool is positioned at a distance from thefirst vertical axis of rotation greater than a distance at which theupper fitting tool is positioned relative to the first vertical axis ofrotation.
 5. The machine according to claim 1, wherein the wall pressingtool comprises the contact element configured to rotate about a relativeaxis and/or having an ogival shape.
 6. The machine according to claim 1,wherein the wall pressing tool is connected rigidly to the upper fittingtool by the connecting arm.
 7. The machine according to claim 1, whereinthe wheel-holder unit includes: a shaft, configured to rotate about thefirst vertical axis of rotation, and a clamping rod, which includes aconical portion, which centers the wheel, whereby, when the wheel islocked so as to rotate as one with the shaft of the wheel-holder unit,the conical portion is pressed on the corresponding rim of the wheel. 8.The machine according to claim 7, wherein the shaft of the wheel-holderunit is a hollow shaft.
 9. The machine according to claim 8, wherein theclamping rod is connectable to the hollow shaft to lock the wheel to thewheel-holder unit.
 10. A machine for fitting and removing a tyre from acorresponding rim of a wheel for a vehicle, comprising: a wheel-holderunit that is rotatable about a first vertical axis of rotation; a baseprovided with a groove, wherein the groove guides a movement of thewheel-holder unit with respect to the base; a column having a guideoriented vertically; an upper arm having a first end and a second end;an upper carriage coupled to the guide of the column and connected tothe first end of the upper arm; an upper operating head, connected tothe second end of the upper arm, rotating about a second axis ofrotation, provided with an upper fitting tool having an elongate shapealong a longitudinal direction, to be operatively inserted between abead of the tyre and an annular edge of the corresponding rim, andprovided with at least one further tool, angularly spaced from the upperfitting tool by a predetermined angle, so that the tools arealternatively selectable by rotating the upper operating head inrespective operating configurations in which they are oriented towardsthe wheel to be positioned in a working position in contact with thetyre by translation of the upper operating head; a lower operating head,coupled to the second end of a lower arm, the second end of the lowerarm being slidably coupled to the column, the lower operating head beingrotatable and provided with a first lower tool and a second lower tool,the first lower tool and the second lower tool being spaced radially bya predetermined angle, to be selectively and alternatively positioned inan operating configuration by rotation of the lower operating head,wherein the first lower tool is configured to adopt an active positionand a rest position, and is rotatable about a fourth axis, transverse toan axis of rotation of the lower operating head, to pass from the restposition to the active position.
 11. The machine according to claim 10,further comprising a wall pressing tool connected to the upper fittingtool, and wherein the upper fitting tool, when selected in the workingposition, is positioned with its longitudinal axis parallel to the firstvertical axis of rotation and wherein the wall pressing tool ispositioned laterally at a predetermined distance relative to a planepassing through the first vertical axis of rotation and the upperfitting tool.
 12. The machine according to claim 10, wherein the firstlower tool and the second lower tool being spaced radially by 90degrees.
 13. The machine according to claim 12, comprising a wallpressing tool connected to the upper fitting tool, wherein the at leastone further tool includes a removal tool and an upper bead breaker disc,and wherein the upper fitting tool, the upper bead breaker disc and theremoval tool are angularly spaced at predetermined angles to bealternatively selectable by rotation, thereby defining respectiveoperating configurations wherein the tools are oriented towards thewheel mounted on the wheel-holder unit for being positioned in a workingposition in contact with the tyre by translation of the upper operatinghead: a first operating configuration wherein the upper bead breakerdisc is selected, a second operating configuration wherein the removaltool is selected, a third operating configuration wherein the upperfitting tool and the wall pressing tool are selected.
 14. The machineaccording to claim 13, comprising: a first three-stage actuatoroperatively connected to the upper operating head for rotating itbetween the operating configurations, wherein the first three-stageactuator defines a first stage in which it positions the upper operatinghead in the first operating configuration, a second stage in which itpositions the upper operating head in the second operatingconfiguration, a third stage in which it positions the upper operatinghead in the third operating configuration, thereby defining apredetermined sequence of operating positions as a function of apredetermined direction of rotation of the upper operating head; acontrol unit connected to the first three-stage actuator for controllinga movement from one stage to the other, according to the followingpredetermined sequence of stages: the first stage, the second stage, thethird stage, wherein passage from the first stage to the second stageand the passage from the second stage to the third stage correspond to arotation of the upper operating head according to the predetermineddirection of rotation and the passage from the third stage to the firststage corresponds to a rotation of the upper operating head in anopposite direction to the predetermined direction of rotation.
 15. Themachine according to claim 10, wherein the upper operating head includesa body, which is provided with radial grooves, each radial groove beingin contact with a respective base of a corresponding tool.
 16. Themachine according to claim 15, wherein the radial grooves constitute arotation lock by interference, to prevent an accidental rotation of thetools relative to the upper operating head.
 17. A machine for fittingand removing a tyre from a corresponding rim of a wheel for a vehicle,comprising: a wheel-holder unit rotating about a first vertical axis ofrotation; a base provided with a groove, wherein the groove guides amovement of the wheel-holder unit with respect to the base; a columnhaving a guide oriented vertically; an upper arm having a first end anda second end; an upper carriage coupled to the guide of the column andconnected to the first end of the upper arm; an upper operating head,connected to the second end of the upper arm, provided with at least oneupper fitting tool defining a lever having an elongate shape along alongitudinal direction, to be operatively inserted between a bead of thetyre and an annular edge of the corresponding rim, in an operatingconfiguration in which the at least one upper fitting tool is orientedtowards the wheel, to be positioned in a working position in contactwith the tyre by translation of the upper operating head; a loweroperating head, coupled to the second end of a lower arm and providedwith at least one tool configured to operatively act on a lower bead ofthe tyre, the second end of the lower arm being slidably coupled to thecolumn; a wall pressing tool, connected to the upper operating head andoriented in a direction concordant with the at least one upper fittingtool, for being positioned simultaneously with the at least one upperfitting tool in a working position, wherein the wall pressing tool andthe at least one upper fitting tool are both, simultaneously in contactwith the tyre of the wheel positioned on the wheel-holder unit, whereinthe wall pressing tool is rotatably mounted to a second end of aconnecting arm that is connected to the upper operating head at a firstend.
 18. The machine according to claim 17, comprising a lower carriagecoupled to the guide of the column and connected to the first end of thelower arm, wherein the at least one tool provided in the lower operatinghead includes a lower bead breaker disk.
 19. The machine according toclaim 17, wherein the lower operating head comprises at least two lowertools angularly spaced by predetermined angles for being selectively andalternatively positionable in respective operating positions forrotating the lower operating head.
 20. The machine according to claim19, wherein the at least two lower tools comprise a lower bead breakerdisc and a lower fitting tool.